Novel three-dimensional framework based on Co(II)-azide chains and a tetrapyridyl ligand

A new cobalt(II) coordination polymer with azide and a quadritopic ligand, [Co2(N3)4(TPOM)]n (TPOM = tetrakis(4-pyridyloxymethylene) methane), was solvothermally synthesized and characterized structurally and magnetically. The compound exhibits a three-dimensional framework in which Co(II) chains with alternating double end-on (EO) and double end-to-end (EE) azide bridges are linked by the tetrapyridyl ligand in a bowl-shaped conformation. With both Co(II) and TPOM as 4-connecting nodes, the structure represents the first real example of the 4-connected net topology with point symbol {32·104}{32·4·102·11}2. Magnetic studies demonstrated that the alternating double EO and double EE azide bridges induce ferro- and antiferromagnetic interactions along the chain.